What is the A4 Study?

The purpose of the Anti-Amyloid Treatment in Asymptomatic Alzheimer’s study (the "A4 Study" for short) is to test whether a new investigational treatment, called an anti-amyloid antibody, can slow memory loss caused by Alzheimer’s disease. Amyloid is a protein normally produced in the brain that can build up in older people, forming amyloid plaque deposits. Scientists believe this buildup of deposits may play a key role in the eventual development of Alzheimer’s disease-related memory loss. The overall goal of the A4 Study is to test whether decreasing amyloid with antibody investigational treatment can help slow the memory loss associated with amyloid buildup in some people.

The A4 Study invites older individuals (ages 65-85) who have normal thinking and memory function but who may be at risk for memory loss due to Alzheimer’s disease, but have no outward signs of the disease to participate in the study. We seek to enroll 1,000 adults who have an “elevated” level of amyloid plaque in their brain. Physicians and researchers will use an imaging test called a PET scan to determine whether a potential participant has evidence of this plaque buildup. People who do not show evidence of elevated amyloid in their brains will not be able to participate, but may be asked to participate in a separate study. This group will not receive the investigational drug or placebo (i.e., an inactive substance designed to mimic the appearance of a drug), but will complete the same memory tests every six months to compare changes in cognition over time.

The A4 Study lasts for three years, and participants will be required to visit the clinical research site once a month. Participants will be assigned at random to receive either the investigational drug or a placebo and will be monitored over the course of the three years. All clinical studies, including the A4 Study, may involve some risks associated with participation. If you are considering participating in A4, you will have detailed discussions with physicians and research staff regarding the investigational treatment and other aspects of the A4 Study.

Who is sponsoring the Study?

The A4 Study is a landmark public-private partnership, funded by the National Institute on Aging, Eli Lilly and Company, and several philanthropic organizations. The A4 trial is coordinated by the University of Southern California’s Alzheimer’s Therapeutic Research Institute, with study sites in multiple locations.

A4 Study Organizers

The A4 Study is a landmark public-private partnership, funded by the National Institute on Aging/NIH, Eli Lilly and Company, and several philanthropic organizations. The A4 trial is coordinated by the University of Southern California’s Alzheimer’s Therapeutic Research Institute, with study sites in multiple locations.